WO2003066201A1

WO2003066201A1 - Catchment header and membrane module unit

Info

Publication number: WO2003066201A1
Application number: PCT/JP2003/001241
Authority: WO
Inventors: Hiroyuki Okazaki; Masumi Kobayashi; Kenji Honjou; Katsuyuki Yanone; Manabu Yanou
Original assignee: Mitsubishi Rayon Co., Ltd.
Priority date: 2002-02-07
Filing date: 2003-02-06
Publication date: 2003-08-14
Also published as: US20050218063A1; KR100554056B1; EP1473074A4; US7255788B2; EP1473074B1; JPWO2003066201A1; JP4261364B2; CN1255207C; KR20040089599A; EP1473074A1; DE60313849T2; CN1627981A; DE60313849D1; HK1070854A1

Abstract

A catchment header allowing a plurality of membrane modules to be connected thereto, having a tubular catchment part with a Young's modulus of 4.0 GPa or less for collecting and taking out filtrated liquid from the membrane modules, wherein at least a part of the tubular catchment part is covered with a reinforcement member with a Young's Modulus of 4.0 to 250 GPa, the tubular catchment part of the catchment header is desirably be formed of a synthetic resin, and the cross sectional area thereof perpendicular to the longitudinal direction of the tubular catchment part is desirably 4 to 36 cm2.

Description

Specification

Water collecting header and membrane module unit Technical field

TECHNICAL FIELD The present invention relates to a water collection header and a membrane module unit to which a membrane module is connected and which collects and flows filtered water.

This application is based on Japanese Patent Application No. 2002-31414, the contents of which are incorporated herein. Background art

In water treatment such as water purification treatment and sewage treatment, various methods for solid-liquid separation of treated water using a membrane module equipped with a separation membrane such as a microfiltration membrane or an ultrafiltration membrane have been studied. . When the water to be treated is filtered using the separation membrane, high-quality treated water can be obtained.

When solid-liquid separation of water to be treated is performed using a separation membrane, clogging of the separation membrane due to suspended solids (SS component) progresses as the filtration treatment is continued, so the filtration flow rate decreases or the transmembrane pressure decreases. Rise. In order to recover from such a state, a technique is known in which an air diffuser is provided below the membrane separation apparatus, and air is diffused during filtration or while filtration is stopped.

In Japanese Patent Application Laid-Open Nos. Hei 5-26261-53, Hei 6-342, Hei 6-340, etc., a sheet-like hollow fiber membrane is fixed to a rectangular housing with a resin. Using a hollow fiber membrane module to maintain a constant distance between adjacent membrane modules, perform bubbling from an air diffuser, and apply a stream of water to be treated uniformly to the membrane module to perform stable solid-liquid separation. Is disclosed.

In order to arrange a large number of membrane modules at equal intervals with adjacent membrane modules, a number of membrane modules are connected in a liquid-tight manner to a tubular water collection header with holes for connecting the membrane modules. A method of collecting and removing the filtrate is known.

The water collecting header is made by welding a resin pipe with a resin flat plate with a hole for module connection, or by bending a U-shaped metal sheet into a metal plate. A welded open metal plate or a combination of a metal plate with a hole for module connection and a resin water passage has been devised.

However, when a resin flat plate with a hole for module connection is welded to a resin pipe, the flat plate for module connection can be processed more easily than a metal plate. Mechanical strength is lower than metal of the same shape.

For this reason, if the water collection header is made of a resinous pipe, it is necessary to use a water collection header with a large outer diameter in order to withstand the bending stress applied to the water collection header for a long time due to publishing and washing. However, since the portion not directly involved in the filtration becomes large, the efficiency of membrane integration could not be increased.

Also, if sludge adheres to the membrane surface due to any equipment trouble, when the membrane separation device is pulled up to solve the problem, a larger bending stress than normal acts will be applied, and the water collection header will be damaged Due to concerns, it was necessary to design the catchment header thicker than it could withstand normal use to avoid this, which further reduced the integration efficiency.

Also, a water collecting header in which a metal plate with holes for module connection is welded to a bent metal sheet with a U-shape, a metal plate with holes for module connection, and resin There is a water collection header that combines the water passages of the two types. However, such a water collection header requires a process of drilling a large number of module connection holes continuously in a thick metal plate. Processing is a very difficult task. It is also difficult to weld with low distortion continuously in the longitudinal direction when welding with a thin metal plate.For example, when a water collecting header 70 cm in length is manufactured by welding, due to the thermal distortion of welding, Bending of 5-6 mm occurs in both horizontal and vertical directions. For this reason, it was difficult to orderly arrange a large number of membrane modules on a distorted water collection header.

In addition, there was a concern that the welding would be insufficient, and the joint would peel off after a long period of use, resulting in leakage.

The present invention has been made to solve the above problems, and is lightweight, compact, excellent in workability, and can stably perform solid-liquid separation treatment by a separation membrane for a long period of time. The purpose is to provide a catchment header. Disclosure of the invention

That is, a first gist of the present invention is that a plurality of membrane modules can be connected, and a tubular water collecting portion for collecting and extracting a filtrate from each of the membrane modules is provided. A water collecting header which is not more than 4.0 GPa and at least a part of the tubular water collecting section is covered with a reinforcing member having a longitudinal elastic modulus of 4.0 GPa to 250 GPa. is there.

Further, it is preferable that the tubular water collecting portion is made of a synthetic resin because it can be easily and inexpensively molded.

Further, it is preferable that the cross-sectional area perpendicular to the longitudinal direction of the tubular water collecting portion is 4 to 36 cm ² , since a sufficient amount of filtrate can be flowed in a compact size.

In addition, it is preferable that the tubular water collecting portion is formed by connecting a plurality of members in series, since a water collecting header of an arbitrary length can be obtained.

It is preferable that the reinforcing member is made of any of metal, filler-reinforced plastic, and fiber-reinforced plastic because the strength is high.

A second gist of the present invention is a membrane module unit in which a plurality of membrane modules are connected to the water collection header having the above-described structure.

If the membrane module is a hollow fiber membrane module in which a sheet-like hollow fiber membrane bundle end is accommodated inside a rectangular housing and fixed in a liquid-tight manner with a fixing member, the efficiency of membrane integration can be increased. preferable. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing an example of the water collecting header of the present invention.

FIG. 2 is a sectional view showing an example of the water collecting header of the present invention.

FIG. 3 is a perspective view showing an example of a hollow fiber membrane module used in the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. FIG. 1 is a perspective view showing an example of the water collecting header of the present invention. In FIG. 1, the tubular water collecting part 1 has a membrane module connection part 3 in which a membrane module connection hole 2 is formed in the center. The inside of the tubular water collecting part 1 is hollow, and is configured to collect and flow filtered water from the membrane module. At both ends or one end of the tubular water collecting section 1, filtered water outlets 4 are provided.

The material of the tubular water collecting part 1 is preferably a resin because of easy molding. Examples include thermoplastic resins such as vinyl chloride resin, polyolefin resin, polystyrene resin, ABS resin, polycarbonate resin, polyamide resin, polyester resin, modified polyphenylene ether resin, and polyacetal resin. Since the material of the tubular water collecting part 1 has a complicated shape and the fitting part needs to be liquid-tight, a resin containing no reinforced filler is preferable.

As shown in FIG. 1, the shape of the tubular water collecting section 1 may be a square cross section perpendicular to the longitudinal direction, or may be other polygons, circles, ellipses, etc. It is also possible.

The membrane module connecting portion 3 may be a plate-shaped member having a hole for connecting the membrane module, but may be a projection as shown in FIG. Protrusion is preferable because distortion during molding is small and accuracy can be maintained. Further, in the case of forming a projection, it is preferable to mold the adjacent projections so as to be connected by the connection member 5 because the strength is increased.

FIG. 2 is a sectional view showing an example of the water collecting header of the present invention. As shown in FIG. 2, the tubular water collecting section 1 can easily form a water collecting header of any length by connecting a plurality of members in series to form a single tubular water collecting section. It is preferable because it can be obtained. In the example of FIG. 2, the tubular water collecting part 1 is formed as a single block having a size that allows five membrane modules to be connected, and each block is provided with a protrusion provided at one end thereof. It is configured to fit in a liquid-tight manner through a sealing member 7 inside the block to be sealed. The flanges are fixed at both ends. Filter water outlets 4 are provided at both ends or one end of the flange.

—If the number of membrane modules that can be connected to one block is too large, the length will be too long. On the other hand, if the number of connectable membrane modules is too small, the number of blocks will increase. It is too expensive and uneconomical. Therefore, the number of membrane modules that can be connected to one block is preferably 5 to 20, and more preferably 7 to 15.

The method of joining the blocks is not particularly limited, and may be appropriately selected from a mechanical joining method, a joining method using heat melting, a joining method using an adhesive, and the like according to the assembling processability and intended use. Considering the ease of assembling and disassembling the water collection header and recycling, mechanical joining is preferred.

Examples of mechanical joining methods include screw fastening, pin and retaining ring fastening, snap fitting, press fitting, caulking, and the like. In screw fastening, it is necessary to consider the looseness of the joint due to the resin tape and the creep failure due to overtightening. Although snap fittings are easy to assemble, the spring force of the claws must be constantly applied in order to achieve fluid tightness, and the snap fittings must be designed in consideration of the stress generated at the base of the claws. Therefore, among these mechanical joining methods, a joining method using a pin and a retaining ring that does not generate a permanent residual stress in a joint portion between molded products is particularly preferable.

As the sealing material 7, an O-ring, a flat packing, a V-ring, or the like can be used, but an O-ring having high reliability in sealing performance is preferable. The material of the sealing material 7 is appropriately selected from nitrile rubber, styrene rubber, silicon rubber, fluororubber and the like according to the purpose of use.

The cross-sectional area perpendicular to the longitudinal direction of the tubular water collecting section 1 is too thin if the pressure loss becomes large, making it difficult to increase the filtration rate.On the other hand, if it is too thick, the membrane integration efficiency will decrease. et al., it is preferable that the ^{4~ 3 6 cm 2, 9~ 2} 5 cm 2 and child and is more preferable.

A reinforcing member 6 is arranged around the tubular water collecting part 1. The shape of the reinforcing member 6 is not necessarily limited as long as the required strength is obtained; however, it is preferable to arrange the reinforcing member 6 so as to surround the tubular water collecting portion 1 along the outer diameter of the tubular water collecting portion 1. . Further, the reinforcing member 6 may surround the entirety of the tubular water collecting portion 1, but it is preferable that the reinforcing member 6 be arranged so as to surround the portion other than the connecting portion 3 of the membrane module because the shape can be simplified. +

Further, the reinforcing member 6 may have a mesh shape or a lattice shape as long as the necessary strength is maintained. The reinforcing member 6 prevents deformation of the water collecting header 1 against bending stress and rotating moment generated in the water collecting header, and its strength is determined by a tensile or compressive stress perpendicular to the longitudinal direction of the reinforcing member 6. When applied, the modulus of elasticity, expressed as the ratio of the stress to the strain length in that direction, is 4.0 to 250 GPa.

The bending stress that is assumed to be applied when the water collection header is used is about 60 to 10 OMPa. Therefore, if the longitudinal elastic modulus of the reinforcing member 6 is smaller than 4.0GPa, the strength is insufficient for long-term use. On the other hand, a material having a longitudinal elastic modulus of more than 250 GPa is not preferable because the hardness is too high and the material is brittle. By arranging the reinforcing member 6 around the tubular water collecting part 1, the tubular water collecting part 1 can have a longitudinal elasticity coefficient of 4.0 GPa or less. While maintaining the strength of the header, it can be compacted and easily processed.

The modulus of longitudinal elasticity is determined according to the material according to JISK7113 (plastic tensile test method), JISZ2241 (metallic material tensile test method), JISK7054 (glass fiber reinforced plastic tensile test method). Method), JISK7703 (Carbon fiber reinforced plastic tensile test method) and other test methods.

The material of the reinforcing member 6 is preferably excellent in corrosion resistance, strength, and workability, and is preferably made of any of metal, filler-reinforced plastic, and fiber-reinforced plastic. Examples of metals include stainless steel, titanium, aluminum alloy, magnesium alloy, and the like.Examples of filler-reinforced plastic or fiber-reinforced plastic include ABS resin, polyamide resin, polycarbonate resin, polyacetal resin, and modified polyphenylene. Fillers or glass fibers, carbon fibers, or the like may be contained in direne ether resins or the like, and those having a longitudinal elastic modulus in the above range may be appropriately selected from these.

In preparing the membrane module unit, the membrane module to be connected is not particularly limited, but it is preferable to use a flat membrane module because it has good cleaning properties, is not easily clogged, and can be stably filtered for a long period of time. Above all, as shown in FIG. 3, the hollow fiber membrane 9 was developed in a flat shape, and the end was fixed to the housing 11 using a fixing member 10. It is more preferable to use the hollow fiber membrane module 12 because the efficiency of integration can be increased while maintaining good cleaning properties.

As the material of the hollow fiber membrane, conventionally known materials such as cellulose, polyolefin, polysulfone, polybutyl alcohol, polymethyl methacrylate, polyvinylidene fluoride, and polytetrafluoroethylene can be used. Polyolefin-based materials having high elongation, such as polyethylene and polypropylene, are preferably used from the viewpoints of workability, responsiveness to shaking during air diffusion, and the like.

The method of connecting the membrane module to the water collecting header is not particularly limited as long as it can be connected in a liquid-tight manner. Fixing by inserting the outlet is preferable because it can be fixed in a liquid-tight manner with a simple structure, and the membrane module can be attached and detached. The number of collecting headers can be any number according to the shape of the membrane module and the number of filtered water outlets, etc., but the flow of filtrate from each membrane module to the collecting header should flow as evenly as possible. Is preferably provided. For example, as shown in the hollow fiber membrane module shown in Fig. 3, when there are filtered water outlets 8 at both ends of the hollow fiber membrane, two water collection headers should be provided for one membrane module unit. Further, in FIG. 3, there is a filtered water outlet 8 at one end of the water collecting pipe at both ends of the hollow fiber membrane, but the filtered water outlet 8 may be provided at both ends of the water collecting pipe. In that case, it is better to provide four water collection headers per membrane module unit.

Further, the membrane modules can be arranged in a staggered manner. In this case, a single water collection header with holes for connecting membrane modules in a staggered state can be used, or the two water collection headers can be shifted and arranged.

In the case where a membrane module unit is formed by using a sheet-shaped hollow fiber membrane module developed in a flat shape, it is preferable from the viewpoint of cleaning efficiency that the sheet surface is arranged in a vertical direction. At this time, the hollow fiber membrane is arranged so that the fiber axis direction is horizontal or vertical.

Hereinafter, the present invention will be described specifically with reference to examples.

<Example 1> An ABS resin (trade name: Diabet AB S, SW3, manufactured by Mitsubishi Rayon Co., Ltd.) is injection-molded, and the structure shown in Fig. 2 has a nearly square cross-section perpendicular to the longitudinal direction and a substantially square shape. Was made.

The number of membrane modules to be connected per block was set to 10, four blocks were fitted together via a seal material composed of an NBR rubber O-ring, and the adjacent flanges were fixed with 4 mm screws.

The shape of the flange was a substantially square with a side of 4 cm and a thickness of 4 mm. The filtered water outlets were fitted to both ends of the tubular water collecting section via seal materials made of NBR rubber O-rings, and fixed with 4 mm screws.

Along the entire length of this tubular water collecting part, surrounding the part excluding the membrane module connection part, a stainless steel plate with a vertical elasticity coefficient of 2000? .5 cm, width 4.5 cm, length 84 cm.

'The horizontal and vertical distortions of the water collection header manufactured in this example with respect to the longitudinal center line were less than 1.5 mm in both the horizontal and vertical directions.

Also, most Omagari moment when a uniformly distributed load of 9. 8 X 1 0 ² NZm the catchment header is applied is 0. 9 N · m, the maximum track stress is an approximately 8 7 MP a, broken It has a stress of 1 Z5 or less, which leads to breakage, and has sufficient strength to prevent breakage during use. Industrial applicability

According to the water collecting header of the present invention, at least a part of the tubular water collecting part is covered with a reinforcing member having a longitudinal elastic modulus of 4.0 GPa to 250 GPa, so that it is lightweight and compact. The solid-liquid separation process using the separation membrane can be stably performed over a long period of time because of its excellent workability, high dimensional accuracy, and sufficient strength.

Claims

The scope of the claims

1. A plurality of membrane modules can be connected and have a tubular water collecting part for collecting and extracting the filtrate from each membrane module, and the longitudinal elastic modulus of the tubular water collecting part is 4. O GPa or less. A water collecting header, wherein at least a part of the tubular water collecting part is covered with a reinforcing member having a longitudinal elastic modulus of 4.0 GPa to 250 GPa.

2. The water collecting header according to claim 1, wherein the tubular water collecting part is made of a synthetic resin.

3. The water collecting header according to claim 1, wherein a cross-sectional area perpendicular to a longitudinal direction of the tubular water collecting part is 4 to 36 cm ² .

4. The water collecting header according to any one of claims 1 to 3, wherein the tubular water collecting part is connected in series by a plurality of members.

5. The water collecting header according to any one of claims 1 to 4, wherein the reinforcing member is made of any one of a metal, a filler reinforced plastic, and a fiber reinforced plastic.

6. The water collecting header according to any one of claims 1 to 5, further comprising a projecting membrane module connection portion.

7. The water collecting header according to claim 6, wherein the adjacent projecting membrane module connecting portions are connected to each other by a connecting agent! / Puru.

8. A membrane module unit comprising a plurality of membrane modules connected to the water collection header according to any one of claims 1 to 7.

9. The membrane module unit according to claim 8, wherein the membrane module accommodates an end portion of a sheet-like hollow fiber membrane bundle inside a rectangular housing and is liquid-tightly fixed by a fixing member. It is a hollow fiber membrane module.